PROTEIN SENSITIZATION OR ANAPHYLAXIS 225 



extracts they are not strictly specific. It will be readily 

 understood that it is difficult to obtain organ extracts 

 wholly free from the blood of the same animal. 



That the crystalline lens contains proteins different from 

 those found in any other part of the body was demonstrated 

 some years ago by Uhlenhuth, by the precipitin reaction, 

 and it was believed that the proteins of the crystalline lens 

 are identical in all animals. This was apparently confirmed 

 by anaphylactic tests, as shown by the work of Andrejew 1 

 and that of Kraus and Sohma. 2 Guinea-pigs can be sensi- 

 tized with the proteins of their own lenses, or with those of 

 other animals, and sensitization with the proteins of the 

 lens from any animal responds to the same from any animal. 

 The question whether the proteins of the crystalline lens 

 are identical in all animals is of the greatest biological 

 interest. The precipitin and the first sensitizing tests 

 seemed to establish this belief, but quantitative experi- 

 ments, such as those of Kapsenberg, 3 indicate that there are 

 slight differences in the proteins of the crystalline lens from 

 different species. Kapsenberg, after reviewing the literature 

 and detailing his own work, concludes: (1) Guinea-pigs are 

 easily and uniformly sensitized with the lens substance of 

 other animals. The dose on reinjection necessary to induce 

 fatal anaphylactic shock is small. 4 (2) Guinea-pigs may be 

 sensitized to the protein of their own lenses, but this is 

 done with difficulty and the fatal dose on reinjection is 

 large (40 mg.). (3) The proteins of the crystalline lens are 

 specific, but not markedly so. Dunbar finds that the 

 specificity of fish proteins is not so marked as those from 

 mammals. 



Rosenau and Anderson 5 succeeded in sensitizing guinea- 

 pigs to placental tissue from the same animal, and Locke- 

 mann and Thies 6 sensitized rabbits to the serum of the 



1 Arb. aus d. Kaiserl. Gesundheitsamte, xxx, 450. 



2 Wien. klin. Woch., 1908, 1084. 



3 Zeitsch. f. Immunitatsforschung, 1912, xv, 518. 



4 In one instance as low as 2.5 mg. of protein but usually 6 mg. 



5 Hygienic Laboratory Bulletin, No. 45. 

 e Biochem. Zeitsch., xxv. 



15 



